Question

Define extinction angle in power electronics

Answer 1

In power electronics, the load (resistance R1 and inductance L1) is fed to the voltage source V1 via thyristor X1.

The principal characteristic of the circuit is that the current is not in phase with the voltage. This fact is due to the inductive component of the load.

The firing pulse is applied to the gate of thyristor X1 (trigger pin) at instant defined as α. It remains in the ON state until the load current tries to go to a negative value. This instant is defined as angle extinction β. 

Answer 2

In power electronics extinction angle is one where thyristor gets switched off in spite of being reverse biased.

The load is fed for the voltage source through the thyristor. The firing pulse is applied to the gate of the thyristor. It remains in the ON state till the load current tries to go to a negative value. This instant is defined as the angle extinction.